// Muduo - A reactor-based C++ network library for Linux
// Copyright (c) 2010, Shuo Chen.  All rights reserved.
// http://code.google.com/p/muduo/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
//   * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//   * Neither the name of Shuo Chen nor the names of other contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


#ifndef CLUSNET_BASE_BLOCKINGQUEU_H
#define CLUSNET_BASE_BLOCKINGQUEU_H

#include <clusnet/base/Mutex.h>

#include <deque>
#include <condition_variable>
#include <cassert>

namespace clusnet
{
namespace base
{

// thread safe
template<typename T>
class BlockingQueue final
{
    public:
        BlockingQueue(const BlockingQueue<T>&) = delete;
        BlockingQueue<T>& operator= (const BlockingQueue<T>&) = delete;
        BlockingQueue() = default;
        ~BlockingQueue() = default;

    public:
        void put(const T& x)
        {
            std::lock_guard<Mutex>  lock(mutex_);
            queue_.emplace_back(x);
            notEmpty_.notify_one();
        }

        void put(T&& x)
        {
            std::lock_guard<Mutex>  lock(mutex_);
            queue_.emplace_back(std::move(x));
            notEmpty_.notify_one();
        }

        T take()
        {
            std::unique_lock<Mutex> lock(mutex_);
            notEmpty_.wait(lock, [this]{ return !queue_.empty(); });
            assert(!queue_.empty());
            T front(std::move(queue_.front()));
            queue_.pop_front();
            return front;       // RVO
        }

        size_t size() const
        {
            std::lock_guard<Mutex>  lock(mutex_);
            return queue_.size();
        }

    private:
        mutable clusnet::base::Mutex              mutex_;
        std::condition_variable_any     notEmpty_;
        std::deque<T>                   queue_;
};
}
}

#endif 
